//-----------------------------------------------------------------------------
// Class:	bit.*** in NPL
// Authors:	ported by LiXizhi
// Emails:	LiXizhi@yeah.net
// Date:	2008.5.10
// Desc: Port note: the test is passed. "stdint.h" is added for this application from the web. 
// A modified lua 5.1.3 core to allow string.format("%x") to work for entire 52 bits, instead of 31 bits in the official release
//-----------------------------------------------------------------------------
/*
** Lua BitOp -- a bit operations library for Lua 5.1/5.2.
** http://bitop.luajit.org/
**
** Copyright (C) 2008-2012 Mike Pall. All rights reserved.
**
** Permission is hereby granted, free of charge, to any person obtaining
** a copy of this software and associated documentation files (the
** "Software"), to deal in the Software without restriction, including
** without limitation the rights to use, copy, modify, merge, publish,
** distribute, sublicense, and/or sell copies of the Software, and to
** permit persons to whom the Software is furnished to do so, subject to
** the following conditions:
**
** The above copyright notice and this permission notice shall be
** included in all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
**
** [ MIT license: http://www.opensource.org/licenses/mit-license.php ]
*/

#define LUA_BITOP_VERSION	"1.0.2"

#define LUA_LIB
#include "lua.h"
#include "lauxlib.h"

#ifdef _MSC_VER
/* MSVC is stuck in the last century and doesn't have C99's stdint.h. */
typedef __int32 int32_t;
typedef unsigned __int32 uint32_t;
typedef unsigned __int64 uint64_t;
#else
#include <stdint.h>
#endif

typedef int32_t SBits;
typedef uint32_t UBits;

typedef union {
	lua_Number n;
#ifdef LUA_NUMBER_DOUBLE
	uint64_t b;
#else
	UBits b;
#endif
} BitNum;

/* Convert argument to bit type. */
static UBits barg(lua_State *L, int idx)
{
	BitNum bn;
	UBits b;
#if LUA_VERSION_NUM < 502
	bn.n = lua_tonumber(L, idx);
#else
	bn.n = luaL_checknumber(L, idx);
#endif
#if defined(LUA_NUMBER_DOUBLE)
	bn.n += 6755399441055744.0;  /* 2^52+2^51 */
#ifdef SWAPPED_DOUBLE
	b = (UBits)(bn.b >> 32);
#else
	b = (UBits)bn.b;
#endif
#elif defined(LUA_NUMBER_INT) || defined(LUA_NUMBER_LONG) || \
      defined(LUA_NUMBER_LONGLONG) || defined(LUA_NUMBER_LONG_LONG) || \
      defined(LUA_NUMBER_LLONG)
	if (sizeof(UBits) == sizeof(lua_Number))
		b = bn.b;
	else
		b = (UBits)(SBits)bn.n;
#elif defined(LUA_NUMBER_FLOAT)
#error "A 'float' lua_Number type is incompatible with this library"
#else
#error "Unknown number type, check LUA_NUMBER_* in luaconf.h"
#endif
#if LUA_VERSION_NUM < 502
	if (b == 0 && !lua_isnumber(L, idx)) {
		luaL_typerror(L, idx, "number");
	}
#endif
	return b;
}

/* Return bit type. */
#define BRET(b)  lua_pushnumber(L, (lua_Number)(SBits)(b)); return 1;

static int bit_tobit(lua_State *L) { BRET(barg(L, 1)) }
static int bit_bnot(lua_State *L) { BRET(~barg(L, 1)) }

#define BIT_OP(func, opr) \
  static int func(lua_State *L) { int i; UBits b = barg(L, 1); \
    for (i = lua_gettop(L); i > 1; i--) b opr barg(L, i); BRET(b) }
BIT_OP(bit_band, &= )
BIT_OP(bit_bor, |= )
BIT_OP(bit_bxor, ^= )

#define bshl(b, n)  (b << n)
#define bshr(b, n)  (b >> n)
#define bsar(b, n)  ((SBits)b >> n)
#define brol(b, n)  ((b << n) | (b >> (32-n)))
#define bror(b, n)  ((b << (32-n)) | (b >> n))
#define BIT_SH(func, fn) \
  static int func(lua_State *L) { \
    UBits b = barg(L, 1); UBits n = barg(L, 2) & 31; BRET(fn(b, n)) }
BIT_SH(bit_lshift, bshl)
BIT_SH(bit_rshift, bshr)
BIT_SH(bit_arshift, bsar)
BIT_SH(bit_rol, brol)
BIT_SH(bit_ror, bror)

static int bit_bswap(lua_State *L)
{
	UBits b = barg(L, 1);
	b = (b >> 24) | ((b >> 8) & 0xff00) | ((b & 0xff00) << 8) | (b << 24);
	BRET(b)
}

static int bit_tohex(lua_State *L)
{
	UBits b = barg(L, 1);
	SBits n = lua_isnone(L, 2) ? 8 : (SBits)barg(L, 2);
	const char *hexdigits = "0123456789abcdef";
	char buf[8];
	int i;
	if (n < 0) { n = -n; hexdigits = "0123456789ABCDEF"; }
	if (n > 8) n = 8;
	for (i = (int)n; --i >= 0;) { buf[i] = hexdigits[b & 15]; b >>= 4; }
	lua_pushlstring(L, buf, (size_t)n);
	return 1;
}

static const struct luaL_Reg bit_funcs[] = {
	{ "tobit", bit_tobit },
	{ "bnot", bit_bnot },
	{ "band", bit_band },
	{ "bor", bit_bor },
	{ "bxor", bit_bxor },
	{ "lshift", bit_lshift },
	{ "rshift", bit_rshift },
	{ "arshift", bit_arshift },
	{ "rol", bit_rol },
	{ "ror", bit_ror },
	{ "bswap", bit_bswap },
	{ "tohex", bit_tohex },
	{ NULL, NULL }
};

/* Signed right-shifts are implementation-defined per C89/C99.
** But the de facto standard are arithmetic right-shifts on two's
** complement CPUs. This behavior is required here, so test for it.
*/
#define BAD_SAR		(bsar(-8, 2) != (SBits)-2)

int luaopen_bit_local(lua_State *L)
{
	UBits b;
	lua_pushnumber(L, (lua_Number)1437217655L);
	b = barg(L, -1);
	if (b != (UBits)1437217655L || BAD_SAR) {  /* Perform a simple self-test. */
		const char *msg = "compiled with incompatible luaconf.h";
#ifdef LUA_NUMBER_DOUBLE
#ifdef _WIN32
		if (b == (UBits)1610612736L)
			msg = "use D3DCREATE_FPU_PRESERVE with DirectX";
#endif
		if (b == (UBits)1127743488L)
			msg = "not compiled with SWAPPED_DOUBLE";
#endif
		if (BAD_SAR)
			msg = "arithmetic right-shift broken";
		luaL_error(L, "bit library self-test failed (%s)", msg);
	}
#if LUA_VERSION_NUM < 502
	luaL_register(L, "bit", bit_funcs);
#else
	luaL_newlib(L, bit_funcs);
#endif
	return 1;
}

